Differential SP4 expression and HSP60 abundance in buccal swabs from patients with schizophrenia

Schizophrenia (SCZ) is heterogenous and polygenic, making it difficult to diagnose and treat. This is expected as diagnostic criteria are solely based on behavioral markers. There is a critical need for easy-to-collect biomarkers that aid in treatment. To identify potential biomarkers, we recruited patients with SCZ and controls. Using buccal cell lysates, we performed real-time quantitative polymerase chain reaction and identified significant differences in Sp4 mRNA between patients and controls. Targeted mass spectrometry identified increased heat shock protein 60 (HSP60) in SCZ samples. To determine the utility of Sp4 mRNA and HSP60 protein as biomarkers, we evaluated their relationship with symptom severity and aberrant cognitive processes. Correlational analyses revealed that elevated Sp4 mRNA and HSP60 protein define a subgroup of patients with SCZ who demonstrate symptomology and poor memory. These data support buccal cell Sp4 mRNA and HSP60 protein as easy-to-collect, candidate SCZ biomarkers for a subset of patients.